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Haillant O.,Atlas Material Testing Technology GmbH | Dumbleton D.,Atlas Material Testing Technology LLC | Zielnik A.,Atlas Material Testing Technology LLC
Solar Energy Materials and Solar Cells | Year: 2011

A mathematical model based on the Arrhenius equation is used to determine the acceleration of temperature dependent degradation processes affecting the performance of polymeric PV modules in artificial weathering over two benchmark climates. To take into account the natural variability of stress factors in outdoor environments, equivalent temperatures corresponding to photothermally and thermally activated degradation processes were calculated using detailed temperature and radiation data for these modules. Temperature and radiation data for the accelerated laboratory weathering part were derived from the implementation of an international standard for the weathering of plastics. Depending on the value of the activation energy and the reference outdoor location, acceleration factors ranging from 3 to 11 were calculated. © 2011 Elsevier B.V. All rights reserved.

Haillant O.,Atlas Material Testing Technology GmbH
Solar Energy Materials and Solar Cells | Year: 2011

Although polymer and organic photovoltaic modules represent a promising alternative to technologies based on inorganic semiconductors in terms of versatility and cost, reliable methods to test and improve their long-term stability in end-use environments still need to be developed. To be compatible with product development cycles and time-to-market constraints, the testing should provide data quickly enough to allow for changes in formulation and/or design. Over the last decades, various established large-scale industries have been refining approaches to estimate the service life of polymer-based materials and products. State-of-the-art methodologies rely on outdoor and laboratory accelerated aging techniques that combine factors of stress in a similar way as seen in the end-use environment, though at increased levels. However, testing procedures developed by the organic electronics industry in general and OPV in particular do not systematically apply the basic principles of accelerated testing that would ensure the reproduction of failure modes seen in real life. This paper takes a close look at the crucial components of a comprehensive test program aimed at estimating the long-term durability of OPV products. © 2010 Elsevier B.V. All rights reserved.

Modern laboratory weathering devices are able to simulate and control the primary weathering factors - sun, heat and water - simultaneously in suitable test cycles. To ensure a high quality weathering test, the test methods and laboratory practices must satisfy state-of-the-art requirements. Despite the large number of existing standards, it may be necessary to develop new tailor-made test methods. A proven process is available to do so. Laboratory and outdoor weathering should also always be combined to obtain reliable and quantitative statements about correlation and acceleration. The use of high irradiance, the use of pyrometers for temperature measurement and calibration, as well as improved spectral distributions and test cycles, contribute to the technical progress of weathering technology.

Kockott D.,Wissenschaftliche Beratung | Schoenlein A.,Atlas Material Testing Technology GmbH
Polymer Testing | Year: 2012

Solar simulators generate radiation which should simulate a defined "reference sun" as perfectly as possible, and most important is the fitting to the spectral distribution. So far, the fitting is described verbally only, e.g. in standards concerning artificial weathering, and the user has to decide for himself whether the spectral distribution E(λ) indicated by the producer of the solar simulator agrees well enough with the "reference sun" for his specific application. Occasionally, the classification describes the fitting to a wanted "reference sun" only insufficiently (e.g. qualification approvals for photo voltaic modules). This paper deals with a procedure for the determination of factors characterising the grade of fitting in quantity. For various solar simulators which are commercially available (e.g. for artificial weathering tests or design qualification tests), characteristic factors for different wavelength ranges are indicated, and a proposal is made for a classification regarding the grade of fitting of the spectral distribution of solar simulators to a defined "reference sun". As examples of characteristic factors regarding action spectra with especially distinct wavelength dependence, characteristic factors for the UV erythema and the CO formation of PE are given. © 2012 Elsevier Ltd. All rights reserved.

Atlas Material Testing Technology GmbH | Date: 2013-07-03

In a weathering chamber, a UV radiation device is arranged and at least one sample can be arranged in a sample plane spaced apart from the UV radiation device. The UV radiation device has a plurality of UV light emitting diodes (UV LEDs) containing two or more classes of UV LEDs having different emission bands. The emission bands are chosen in such a way that a spectral distribution with which a specific spectral UV characteristic is approximated can be obtained in the sample plane.

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